It is well known that chemical and physical analysis of a machine fluid can provide information about the condition of the fluid as well as the wear status of the machine in which the fluid is used. Machine fluid analysis is widely used for determination of lubricant condition, lubricant contamination and wear status in engines, drive components and hydraulic systems in fleet or industrial service. For example, lubrication oil analysis is widely used for railroad engines and is conducted by the military on most motorized equipment including aircraft and naval engines and lubricated drive components. In industry, commercial fluid analysis providers offer fluid analysis service for engine and drive train lubricants as well as hydraulic fluids.
However, traditionally, an oil sample has been taken from the lubricant reservoir on the engine being analyzed, with fluid parameters then measured in the laboratory. To avoid inefficiencies and difficulties associated with such batch analysis, it is desirable to develop systems and devices capable of operation on board a machine to provide continuous and real time monitoring of machine fluids.
One type of fluid analysis, x-ray fluorescence analysis, has the potential to be used to quantify trace amounts of materials in machine fluids, provided the x-ray fluorescence meter employed is sufficiently sensitive to the material to be detected. However, for a variety of reasons, many x-ray fluorescence meter designs are not readily applicable for on-board machine fluid analysis.
For example, while not as important for most laboratory scale spectrometer applications, for an on-board machine fluid application, it is advantageous to have a compact spectrometer. However, the sensitivity of a spectrometer is typically compromised by attempts to limit its size because, as the device becomes smaller, components necessarily get closer together, increasing the relative significance of noise. In addition, a smaller device may be more susceptible to breaking or failure from the potentially harsh environment on-board a machine. As a final example, in order to be feasible for dedicated application to individual machines, an x-ray fluorescence meter must be economical to manufacture.
Therefore, a need exists for an x-ray fluorescence spectrometer that is both compact and sensitive so as to be useful in on-board machine fluid analysis. A need also exists for an x-ray fluorescence spectrometer that is capable of meeting the rigors of on-board application yet is economical and efficient to construct. The invention described in the above-mentioned application Ser. No. 10/1041,331 filed Jan. 7, 2003 addresses one or more of these or other needs.
In addition to lubricants and hydraulic fluids in machines, certain machines requiring fuel are totally dependent on the condition of fuel supplied to achieve optimum performance. This is particularly true in the marine propulsion maintenance industry, wherein both lube oil analysis and bunker fuel analysis are important for proper maintenance and operation of a ship. In this industry, and in others as well, there is value in having the ability to simultaneous perform analysis of different samples. It is also advantageous to have multi-analysis capabilities where one analysis is automated ongoing in-line analysis, and another provides on-board manual analysis of fuels and lubricants. At the same time, there remains the need for apparatus that is reasonably sturdy, accurate, reliable, inexpensive and compact. The present invention is addressed to one or more of these needs.